Solving Drain & Sewer Problems

Public Sewer

Are your drains blocked, cracked or broken? Are your sewers causing you serious structural problems or is the fix a quick one you can tackle yourself? Follow our guide to finding a solution for both small and serious problems.

By Caroline Rodrigues

Got A Blockage?

For sink, bath or shower blockages due to hair or grease, using proprietary cleaners, plunging or unscrewing the trap for a good clear out can do the trick, but blockages don't just occur inside and good, regular maintenance is essential. Outside the house, leaves blocking a downpipe can be hoiked out, and blockages rodded away fairly easily. But if you suspect more serious problems you’ll have to call in the professionals.

What Are The Signs Of Drain Problems?

Signs of drain problems include:

  • Difficulties when flushing the loo.
  • Water draining away slowly from sinks.
  • Unpleasant smells and water collecting on surfaces such as a patio from overflowing drains, gulleys and manholes.
  • In serious cases of leaking drains, you might see evidence of subsidence including cracks in brickwork, windowsills, driveways, or sunken steps.

What’s Causing The Problem?

Where shall we start? A straightforward blockage is likely but underlying causes could be general deterioration of pipes and joints due to age.

  • In Victorian houses, the salt-glazed clayware drains are over 100 years old and cracks or porous joints can occur, while cast iron pipes can corrode.
  • In 1960s properties, pitch fibre pipes were used, and these can gradually deteriorate, deflating from their original circular shape, blistering or collapsing.
  • Then there are badly built drains with poorly designed manholes or a poor fall from the pipes.
  • Broken, collapsed, deformed or cracked pipes can be due to movement in the ground, or pipes can fracture due to a heavy vehicle driving over the ground above.
  • And tree roots can grow into the drains through pipe joints, cracked pipes or manhole walls.

What Damage Happens Next?

As the water leaks away from a pipe, it takes soil with it, resulting in soft ground and sometimes subsidence. If neighbouring properties are also affected by drain problems, or if there’s widespread flooding, the problem could be from the sewer.

How To Investigate Further

  • If it’s unclear where the problem is, a drainage company will perform a simple check, lifting the manhole covers and running water through to identify blockages or leakage. Coloured dyes can identify flows from different sections of the drain network.
  • The lower end of the drain can be plugged, and water run through to check whether the drain holds it, or whether it leaks away. When the plug is removed, the water should flow away quickly.
  • The next step is to send a CCTV camera down the drain to inspect for blockages or a collapse. It is sometimes mounted on a crawler unit. This is taped so you can have an evening’s enjoyment watching a feature film of your own drains.

Who Is Responsible?

Home owners are responsible for drains up to the point where pipework meets public sewers. If you call the local water company (find yours at Water UK) they will confirm whether blocked pipework belongs to them (in which case they will clear it) and they may offer a private clearing service for the section that’s your responsibility. Check your house insurance to see if you are covered for problems with drains.

The local authority: if you suspect the problem isn’t on your property but perhaps is coming from a neighbouring one, contact your local environmental health department for advice. The authority has powers to investigate the matter, carry out repairs and recover costs from the home owner.

Water companies: drains carry waste from toilets, bathrooms and kitchens from your home. Sewers take this waste plus surface water away from more than one property. At present sewers can be publicly or privately maintained. If publicly maintained, repairs and maintenance are the job of the local water company. From a proposed date of October 2011, private sewers will be the responsibility of the water companies. Until then, a private sewer is the joint responsibility of the properties that drain into it, up to the point where it joins a public sewer. Private sewers may run through gardens rather than under the road so you could be responsible for drainage pipes beneath a neighbour’s land. Ask your local council whether the sewer is privately owned.


What’s The Solution?

  • The simplest procedures to remove a blockage use drainage rods, high pressure jetting or cutters on rotating steel rods.If the cause is tree roots, remote-control cutting tools can slice through them, then the drain can be lined to prevent a further occurrence.
  • A broken or cracked drain can be relined to prevent further problems and in many cases the repair can be done without the disruption of excavation. Methods include a CIPP (Cured In Place Pipe), which is inserted, deflated, into the original pipe, then inflated to line it. A polyester sock with flexible internal liner does a similar job, as does UV lining, which is winched through the pipe, then cured using a UV light on a train pulled through the pipe.
  • An isolated repair can treat just one section of the pipe, for example with a fibreglass mat coated with epoxy resin, pushed into position then cured.
  • Dynorod’s patented ‘in2’ system replaces the existing pipe without excavation, pushing small segments of new pipe one after another along the drain run via a manhole or small hole.
  • If excavation is needed, this can be done by hand or with mechanical diggers. New PVCu or vitrified clayware pipes can be fitted.

Need To Know

  • You must notify your local authority building control department of building work or works to repair, reconstruct or alter the course of a drain.
  • Traditional clay-pipe drainage run into site-built manholes with brick or concrete chambers while in newer houses plastic preformed inspection chambers may be used. If there’s no inspection chamber, or if it has been filled in, the drain company may have to dig down to the drains and break in.
  • Septic tanks and soakaways should be de-sludged annually to prevent problems.

Helpful Links

Consumer Council for Water


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